In the video, Holmes, Damper and another man are sitting in a vehicle as they broadcasted live to Facebook.
A woman presumed to be a family member (likely a cousin), Dekenia Thats'my-Attitude Mcneal, also went off on people sharing the video on Holmes' shooting. The two other people in the auto exit the vehicle.
KHOU reported the incident taking place on Easter Sunday circa 2.30 am as Holmes was 'hanging around' with pals in the parking lot of Valero gas station.
Footage seen on social media does not show the moment Holmes was gunned down but does show him slumped over and covered in blood.
Parkland student: Going to school 'feels like jail'
Many were quick to point out clear backpacks had been used in a lot of USA schools since the Columbine school massacre in 1999. Junior Cameron Kasky tweeted a photo of his clear backpack full of tampons Tuesday as a comment on the measure.
Holmes could reportedly be heard in the video telling the woman holding a handgun that she was making him nervous.
"It ain't got no clip, bud", the other man is heard saying.
The unidentified male passenger in the vehicle has not been charged. Damper reportedly told police that she did not believe the gun was loaded. She was previously charged with tampering with evidence after police said she tried to wipe off her hands before testing for gun powder residue.
Houston police told KPRC-TV that they were investigating the incident as an accidental shooting but it will ultimately be for a grand jury to decide the outcome.